[winphone1974]

But the code populating and sending the email is rarely (ever?) Front end code

[fastball]

Sure, but presumably you want your emails to generally match the aesthetic of the rest of your product, which is easier if you can use the same tooling to make them as you do the frontend of your product.

[verdverm]

React doesn't do its own styling though, and since email will not run js, you are basically talking about css at this point

[f-securus]

Maybe that is the secret sauce of this service. They render the email with react and automagically convert that to something that works for email?

[nlh]

I think they literally just use React as a templating language, basically. You write React components and this service renders them down to email-friend HTML. Like SSR but for email.